获取emgu cv中所有计数器的所有点数

Question

我想绘制一个旋转的矩形。 canny图像不是一个计数器，它是一组计数器。所以我想获得所有计数器的所有积分。例如

Points[] pts = points of all counters.

请参阅附图。

Answer 1

canny显示图像中的所有边缘，而不是外部轮廓。这种方式（但不是唯一的）进行物体检测（前景/背景提取）。 以下片段通过使用canny边缘检测器提取对象roi（Min area rect）。关于从otsu门槛出来的canny thresh参数的充分了解。

希望它有所帮助。 Detection result

Image<Gray,byte> imageFullSize = new Image<Gray, byte>(imagePath);
Rectangle roi = new Rectangle(Your Top Left X,Your Top Left Y,Your ROI Width,Your ROI Height);
//Now get a roi (No copy, it is a new header pointing original image
Image<Gray,byte> image = imageFullSize.GetSubRect(roi);
//Step 1 : contour detection using canny
//Gaussian noise removal, eliminate background false détections
image._SmoothGaussian(15);
//Canny thresh based on otsu threshold value: 
Mat binary = new Mat();
double otsuThresh = CvInvoke.Threshold(image, binary, 0, 255, ThresholdType.Binary | ThresholdType.Otsu);
double highThresh = otsuThresh;
double lowThresh = otsuThresh * 0.5;
var cannyImage = image.Canny(lowThresh, highThresh);   
//Step 2 : contour extraction
Mat hierarchy=new Mat();
VectorOfVectorOfPoint contours = new VectorOfVectorOfPoint();
CvInvoke.FindContours(cannyImage,contours,hierarchy,RetrType.External,ChainApproxMethod.ChainApproxSimple);
//Step 3 : contour fusion
List<Point> points=new List<Point>();
for(int i = 0; i < contours.Size; i++)
{
    points.AddRange(contours[i].ToArray());
}

//Step 4 : Rotated rect
RotatedRect minAreaRect = CvInvoke.MinAreaRect(points.Select(pt=>new PointF(pt.X,pt.Y)).ToArray());
Point[] vertices = minAreaRect.GetVertices().Select(pt => new Point((int)pt.X, (int)pt.Y)).ToArray();
//Step 5 : draw result
Image <Bgr,byte > colorImageFullSize =new Image<Bgr, byte>(imagePath);
Image <Bgr,byte > colorImage =colorImageFullSize.GetSubRect(roi);
colorImage.Draw(vertices,new Bgr(Color.Red),2 );